Knowledge of the mechano-electrochemical signals around the cells and solute transport within a tissue is crucial to understanding cell biology, tissue growth and remodeling in vivo or in vitro. Bioreactors are essential for tissue engineering in vitro as the environment of engineered tissue construct could be controlled. Computer simulations are useful for estimation and prediction of the physical signals within the tissue or tissue construct if the environment of the tissue and the tissue properties are known. However, there is virtually no technology which is capable of online characterizing mechano-electrochemical properties of engineered tissue, or controlling physical signals within the tissue. The proposed research activities will fill the gap in this area. The longterm goals of this study are (1) to engineer functional tissues in vitro for implantation in vivo, and (2) to understand the relationship between mechano-chemical environment and tissue growth (Le., growth laws) for connective (e,g" intervertebral disc) tissues. The objective of this proposed project is to develop novel, bioreactor technology that could online monitor the changes in tissue properties as tissue growth in the bioreactor. In this project, a new bioreactor system will be designed and fabricated. New methods and techniques for characterizing of mechano-electrochemical properties of the engineered tissue will be developed.